High-definition athermalization optical lens

Abstract

The utility model discloses a high-definition athermalization optical lens. The optical lens sequentially comprises a front lens group, an aperture diaphragm and a rear lens group from an object side to an image side along an optical axis. The front lens group comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens, wherein the first lens, the second lens and the third lens have negative focal power, and the fourth lens and the fifth lens have positive focal power. And the rear lens group comprises a sixth lens with negative focal power, a seventh lens with positive focal power and an eighth lens with positive focal power. Wherein the third lens, the fourth lens, the sixth lens and the seventh lens are at least combined into two bonding lenses. The optical lens is compact in structure, fully meets the requirement of miniaturization development, successfully solves the problem that miniaturization and high definition of an existing optical lens are difficult to consider at the same time, basically has no thermal out-of-focus phenomenon under various temperature conditions, the imaging quality is kept at a high level all the time, and the optical lens is suitable for large-scale popularization and application. The stability of the lens used in a complex environment is remarkably enhanced, and more excellent use experience is brought to a user.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical lens technical field, especially a kind of high-definition non-thermal optical lens. BACKGROUND

[0002] With the continuous progress of science and technology and the continuous expansion of application field, the status of high-definition optical lens in modern society is more and more prominent. However, most of the current high-definition optical lens is not only bulky but also expensive. At the same time, in the face of complex and variable environmental temperature, especially in high temperature and low temperature environment, the imaging quality of the lens will generally decrease significantly, which also limits the application of the lens to some extent. SUMMARY

[0003] To solve the above problems, the utility model aims at providing a new optical architecture, specifically a high-definition non-thermal optical lens. The architecture uses a small number of lenses and a small volume system, which reduces the production cost and assembly difficulty by reasonably allocating the focal power of each lens and its relative position, and effectively reduces the influence of thermal effect on the imaging quality, thereby improving the stability and reliability of the optical system in complex environment.

[0004] In order to achieve the above purpose, the utility model adopts the technical scheme of:

[0005] A high-definition non-thermal optical lens includes a front lens group with positive focal power, an aperture stop and a rear lens group with positive focal power in order from object plane to image plane.

[0006] The front lens group includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens; wherein:

[0007] The first lens has negative focal power, its object plane is convex, and its image plane is concave.

[0008] The second lens has negative focal power, its object plane is concave, and its image plane can be concave or convex.

[0009] The third lens has negative focal power, its object plane and image plane are both concave.

[0010] The fourth lens has positive focal power, its object plane and image plane are both convex.

[0011] The fifth lens has positive focal power, its object plane is convex, and its image plane can be concave or convex.

[0012] The rear lens group includes a sixth lens, a seventh lens and an eighth lens; wherein:

[0013] The sixth lens has negative focal power, its object plane and image plane are both concave.

[0014] The seventh lens has positive focal power, and both the object side and the image side of the seventh lens are convex;

[0015] The eighth lens has positive focal power, and both the object side and the image side of the eighth lens are convex;

[0016] Wherein, the effective focal length EFFL of the optical lens and the total track length TTL satisfy EFFL / TTL < 0.3;

[0017] The maximum field of view DFOV of the optical lens and the effective focal length EFFL satisfy EFFL / tan(DFOV) > 7.5;

[0018] The third lens, the fourth lens, the sixth lens and the seventh lens at least combine to form a doublet lens group; and at least one aspheric lens is arranged in the optical lens.

[0019] Further, the maximum diameter D max The maximum diameter D max of the lens in the optical lens satisfies D

[0020] At least one of the first lens and the eighth lens is an aspheric lens.

[0021] When the first lens is an aspheric lens, the first lens is a negative meniscus glass lens, which reduces the spherical aberration of the optical system and improves the thermal stability of the system.

[0022] The Abbe numbers of the third lens, the fourth lens, the sixth lens and the seventh lens are VD3, VD4, VD6 and VD7 respectively, and VD3, VD4, VD6 and VD7 satisfy 29 < VD3, VD4 < 45, VD6 < 30 and VD7 > 60.

[0023] The lenses in the optical lens are glass lenses.

[0024] Compared with the prior art, the optical lens has the following beneficial effects:

[0025] The first lens in the optical lens front lens group is a meniscus negative lens, which can effectively reduce the spherical aberration of the system. Meanwhile, the third lens and the fourth lens are combined into a double cemented lens with high refractive index, which corrects the chromatic aberration and further converges the light rays in the off-axis field, reduces the influence of off-axis aberration on the image quality, the fifth lens is a meniscus positive lens, which bears the main optical power of the front lens group, and weakens the overall field curvature of the optical system. Meanwhile, the sixth lens and the seventh lens are combined into a double cemented lens, which corrects the residual chromatic aberration of the front lens group and reduces the air gap between the lenses, thereby compressing the volume of the optical system. Finally, the eighth lens is designed as a glass aspheric lens, or the first lens is designed as a glass aspheric lens, which effectively improves the residual spherical aberration and other off-axis aberrations of the system, further improves the imaging quality, and enhances the thermal stability of the system.

[0026] The optical architecture effectively avoids the incidence of large-angle light rays through reasonable refractive power distribution, reduces the loss of light refraction and scattering. Meanwhile, the architecture significantly reduces the tolerance sensitivity, which means that even if there is a certain deviation in the assembly process, the overall performance and stability of the system can be maintained. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A structure schematic diagram of the optical lens is shown;

[0028] Figure 2 A ray tracing diagram of the optical lens is shown;

[0029] Figure 3 An MTF (modulation transfer function) curve diagram under normal temperature (20 DEG C) conditions is shown;

[0030] Figure 4 An MTF (modulation transfer function) curve diagram under low temperature (-20 DEG C) conditions is shown;

[0031] Figure 5 An MTF (modulation transfer function) curve diagram under high temperature (85 DEG C) conditions is shown;

[0032] Figure 6 A point column diagram under normal temperature (20 DEG C) conditions is shown.

[0033] Figure 7 A distortion schematic diagram A of the embodiment 1 is shown;

[0034] Figure 8 A distortion schematic diagram B of the embodiment 1 is shown;

[0035] Figure 9 An axial chromatic aberration schematic diagram of the embodiment 1 of the utility model is shown.

[0036] Figure 10 A vertical axis chromatic aberration schematic diagram of the embodiment 1 of the utility model is shown.

[0037] Among the above-mentioned drawings include the following marks:

[0038] First lens group G1;First lens L1;Second lens L2;Third lens L3;Fourth lens L4;Fifth lens L5;Aperture stop STOP;Second lens group G2;Sixth lens L6;Seventh lens L7;Eighth lens L8;Prism 01;Protective glass 02;Image chip 03. DETAILED DESCRIPTION

[0039] The technical scheme of the utility model is described in detail below in combination with the drawings and specific embodiments.

[0040] As Figure 1 Indicated, a kind of high-definition athermal optical lens, from object plane to image plane in order to include the front lens group G1 with positive focal power, aperture stop STOP and the rear lens group G2 with positive focal power, equivalent right-angle prism 01, protective glass 02, image chip 03.

[0041] The front lens group G1 includes the first lens L1 with negative focal power, second lens L2 and third lens L3 and the fourth lens L4 and fifth lens L5 with positive focal power.

[0042] The rear lens group G2 includes the sixth lens L6 with negative focal power, the seventh lens L7 with positive focal power and the eighth lens L8. Wherein, third lens, fourth lens, sixth lens and seventh lens at least combination into a group of double cemented lens, and at least one aspherical lens in optical lens. Preferably, at least one of first lens and eighth lens is aspherical lens. When first lens is aspherical lens, it is negative meniscus glass lens, which reduces the spherical aberration of optical system and improves the thermal stability of system. The Abbe numbers of third lens, fourth lens, sixth lens and seventh lens are VD3, VD4, VD6 and VD7 respectively, and VD3, VD4, VD6 and VD7 satisfy: 29 < VD3, VD4 < 45, VD6 < 30, VD7 > 60.

[0043] The lens in the optical lens is all glass lens, and:

[0044] The first lens has negative focal power, its object plane is convex, and its image plane is concave;

[0045] The second lens has negative focal power, its object plane is concave, and its image plane can be concave or convex;

[0046] The third lens has negative focal power, and both its object plane and image plane are concave;

[0047] The fourth lens has positive focal power, and both its object plane and image plane are convex;

[0048] The fifth lens has positive focal power, and its object plane is convex, and its image plane can be concave or convex;

[0049] The sixth lens has negative focal power, and both its object plane and image plane are concave;

[0050] The seventh lens has positive focal power, and both its object plane and image plane are convex;

[0051] The eighth lens has positive focal power, and both its object plane and image plane are convex.

[0052] The aperture stop is located between the front group of lenses and the rear group of lenses, which can significantly reduce optical aberrations.

[0053] The object plane and image plane of the first lens L1 are S1 and S2 respectively; the object plane and image plane of the second lens L2 are S3 and S4 respectively; the object plane and image plane of the third lens L3 are S5 and S6 respectively; the object plane and image plane of the fourth lens L4 are S7 and S8 respectively; the object plane and image plane of the fifth lens L5 are S9 and S10 respectively; the aperture stop STOP is S11; the object plane and image plane of the sixth lens L6 are S12 and S13 respectively; the object plane and image plane of the seventh lens L7 are S14 and S15 respectively; the object plane and image plane of the eighth lens L8 are S16 and S17 respectively; the object plane and image plane of the prism are S18 and S19 respectively; the object plane and image plane of the protective glass are S20 and S21 respectively; and the image plane is S22.

[0054] In the embodiment 1, the first lens is a meniscus negative lens, the second lens is a double-concave negative lens, the fifth lens is a meniscus positive lens, and the eighth lens is a glass aspheric lens.

[0055] In the embodiment 3, the first lens is a negative meniscus aspheric lens. That is, the total length of the system is shortened, and the spherical aberration of the system is reduced.

[0056] The maximum field of view DFOV and the effective focal length EFFL of the optical lens satisfy EFFL / tan(DFOV)>7.5.

[0057] The total optical length TTL of the lens and the effective focal length EFFL satisfy EFFL / TTL<0.3. The maximum diameter D max of the lens in the optical lens satisfies D max / TTL<0.4. Within the range of the above formula, it is beneficial to realize the miniaturization of the optical system.

[0058] In conclusion, the optical structure of the utility model is reasonable, and the distortion is controlled within 1.10%. By reasonably distributing the optical power of each lens, the optical performance of the lens is effectively improved, and good processability is ensured. In addition, the structure has low sensitivity to tolerance, which means that even if there is a certain parameter deviation during manufacturing and assembly, good optical performance stability can be maintained.

[0059] The design not only ensures high-quality optical performance, but also reduces production cost and assembly difficulty, so the utility model has a series of advantages such as high resolution, small structure size and strong practicability.

[0060] The specific implementation is as shown in the following table:

[0061] Table 1 shows the basic structure parameter table of the optical lens of embodiment 1:

[0062]

[0063] Table 1

[0064] In table 1, the eighth lens L8 is an even aspheric lens, and the remaining lenses are spherical lenses, wherein the even aspheric formula is:

[0065]

[0066] In the formula, the parameter c is the curvature corresponding to the radius, r is the radial height of the lens, k is the conic constant, and a2-a6 are the non-spherical coefficients corresponding to the second-twelfth order.

[0067] The preferred values of the even aspheric parameters of the object surface S16 and the image surface S17 of the eighth lens L8 are shown in table 2:

[0068]

[0069] Table 2

[0070] Table 3 shows the curvature radius R, thickness / distance, refractive index Nd and dispersion coefficient Vd of each lens of the optical lens of embodiment 2.

[0071]

[0072] Table 3

[0073] The preferred values of the even aspheric parameters of the object surface S16 and the image surface S17 of the eighth lens L8 are shown in table 4:

[0074]

[0075] Table 4

[0076] In embodiment 3, the present invention uses the first lens L1 instead of the eighth lens L8 as an aspherical lens. This glass aspherical lens is a meniscus negative lens, which reduces the NA value of the optical system, further reduces the overall spherical aberration of the optical system, and improves image quality.

[0077] Table 5 shows the radius of curvature R, thickness / distance, refractive index Nd, and dispersion coefficient Vd of each lens in the optical lens of Example 3. Specific parameters are as follows:

[0078]

[0079] Table 5

[0080] The preferred values ​​of the even-order aspherical parameters of the object plane S1 and image plane S2 of the first lens L1 are as follows:

[0081] As shown in Table 6:

[0082]

[0083] Table 6

[0084] Figure 3 , Figure 4 and Figure 5 This is a schematic diagram of the imaging MTF at different temperatures in Example 1. Figure 3 It can be seen that the MTF of this optical lens is higher than 0.49 across the entire field of view, and within the range of -20℃ to 85℃, the meridional and sagittal curves have good coincidence, the astigmatism is small, and the image quality stability is high.

[0085] Figure 6 This is a dot plot showing the results under normal temperature (20°C) conditions provided in Example 1. (From...) Figure 3 It can be seen that this optical lens has a good effect on correcting aberrations such as chromatic aberration, astigmatism, and field curvature.

[0086] Figure 7 and Figure 8 This is a distortion diagram of Embodiment 1 of the present invention. The maximum distortion of this optical lens is 1.0235%.

[0087] Figure 9 This is a schematic diagram of the axial color difference in Embodiment 1 of this utility model.

[0088] Figure 10 This is a schematic diagram of the transverse chromatic aberration in Embodiment 1 of this utility model. Because this optical structure uses two sets of cemented doublet lenses, the chromatic aberration is relatively small. In actual use, no obvious color separation will appear at the edges of the projected image.

[0089] In conclusion, the optical structure effectively eliminates various optical aberrations by reasonably distributing optical power of the optical lenses with less lenses, guarantees optical image quality, controls the volume of the optical system, and meets the demand of vehicle-mounted miniaturization development.

[0090] The above merely describes preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made by using the content of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

[0091] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

Claims

1. A high-definition, pyrotechnic optical lens, characterized in that, From the object plane to the image plane, the system sequentially includes a front lens group with positive optical power, an aperture stop, and a rear lens group with positive optical power; the front lens group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; wherein: The first lens has negative optical power, its object surface is convex, and its image surface is concave. The second lens has negative optical power, its object surface is concave, and its image surface can be either concave or convex. The third lens has negative optical power, and both its object plane and image plane are concave. The fourth lens has positive optical power, and both its object plane and image plane are convex. The fifth lens has positive optical power, its object surface is convex, and its image surface can be concave or convex. The rear lens group includes a sixth lens, a seventh lens, and an eighth lens; wherein: The sixth lens has negative optical power, and both its object plane and image plane are concave. The seventh lens has positive optical power, and both its object plane and image plane are convex. The eighth lens has positive optical power, and both its object plane and image plane are convex. Wherein, the effective focal length EFFL of the optical lens and the total optical length TTL satisfy EFFL / TTL<0.3; The maximum field of view (DFOV) and effective focal length (EFFL) of the optical lens satisfy the condition that EFFL / tan(DFOV) > 7.

5. The third, fourth, sixth, and seventh lenses are combined to form at least one set of cemented doublet lenses; and the optical lens contains at least one aspherical lens.

2. The high-definition pyrolysis-free optical lens according to claim 1, characterized in that, The maximum diameter D of the lens in the optical lens max The total optical length of the lens satisfies the TTL requirement, D max / TTL<0.

4.

3. A high-definition, pyrotechnic optical lens according to claim 1, characterized in that, At least one of the first lens and the eighth lens is an aspherical lens.

4. A high-definition, pyrotechnic optical lens according to claim 1, characterized in that, When the first lens is used as an aspherical lens, it is a negative meniscus glass lens, which reduces the spherical aberration of the optical system while improving the thermal stability of the system.

5. A high-definition, pyrotechnic optical lens according to claim 1, characterized in that, The Abbe numbers of the third, fourth, sixth, and seventh lenses are VD3, VD4, VD6, and VD7, respectively, and VD3, VD4, VD6, and VD7 satisfy the following conditions: 29 < VD3, VD4 < 45, VD6 < 30, and VD7 > 60.

6. A high-definition, pyrolysis-free optical lens according to claim 5, characterized in that, All lenses in the optical lens are glass lenses.

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